In 1951 the Treaty of San Francisco was signed by the allied countries and Japan, which restored its formal sovereignty. At the same time, the U.S. and Japan signed the Japan-America Security Alliance. By this treaty, USFJ is responsible for the defense of Japan. As part of this agreement, the Japanese government requested that the U.S. military bases remain in Japan, and agreed to provide funds and various interests specified in the Status of Forces Agreement. At the expiration of the treaty, the United States and Japan signed the new Treaty of Mutual Cooperation and Security between the United States and Japan. The status of the United States Forces Japan was defined in the U.S.-Japan Status of Forces Agreement. This treaty is still in effect, and it forms the basis of Japan"s foreign policy. According to academics and experts, the U.S. provision of Japan"s defense allowed Japan to focus domestic spending on their own economy, thereby assisting Japan with becoming one of the most powerful countries economically in the world.

In the Vietnam War, the US military bases in Japan, especially those in Okinawa, were used as important strategic and logistic bases. In 1970, Koza riot occurred against the US military presence in Okinawa. The USAF strategic bombers were deployed in the bases in Okinawa, which was still administered by the U.S. government. Before the 1972 reversion of the island to Japanese administration, it has been speculated but never confirmed that up to 1,200 nuclear weapons may have been stored at Kadena Air Base, Okinawa in the 1960s.

The Japanese government paid ¥217 billion (US$ 2.0 billion) in 2007 as annual host-nation support called .

The U.S. government employs over 8,000 Master Labor Contract (MLC)/Indirect Hire Agreement (IHA) workers on Okinawa (per the Labor Management Organization) not including Okinawan contract workers.

The relocation of the U.S. Marine Corps Air Station Futenma to Henoko was resolved as of December 2013 with the signing of the landfill agreement by the governor of Okinawa. Under the terms of the new U.S.-Japan agreement 5.000 U.S. Marines will be relocated to Guam and 4.000 U.S. Marines to other Pacific locations such as Hawaii or Australia, while some 10.000 Marines will remain on Okinawa.

Exercise participation

The scope and frequency of U.S. Forces Japan participation in major exercises has been rising in recent years. This is largely attributable to the refocus of the U.S. to the Asia-Pacific region, although certain forces, especially the Marine Corps, have never left the region and continue to be heavily involved in theater security and regional stability. United States Pacific Command (USPACOM), the parent command of U.S. Forces Japan, has also taken on larger and broader roles during exercises in Japan, particularly in those exercises on mainland Japan.

U.S. Forces Japan has no control or authority over subordinate command exercises beyond manipulation of Force Protection Condition levels, which is the only area of tactical control residing with U.S. Forces Japan.

U.S. presence debate

U.S. presence on Okinawa

Okinawa makes up only 0.6 percent of the nation’s land area; yet, approximately 62% of U.S. bases in Japan (exclusive use only) are in Okinawa.

Status of forces agreement

73.4% of Japanese citizens appreciate the mutual security treaty with the U.S. and the presence of the USFJ, a small but very vocal portion of the population demand a reduction in the number of U.S. military bases presence.

There is also debate over the Status of Forces Agreement which covers a variety of administrative technicalities blending the systems which control how certain situations are handled between the U.S."s and Japan"s legal framework. SOFA was created to allow both nations the best way to administer legalities, and has worked well over the years.

U.S. service member behavior

Per Okinawa Prefectural Police data, U.S. service members commit far less crimes than local Okinawans. According to the U.S.-Japan Status of Forces Agreement, U.S. personnel who commit crimes off-duty and off-base, are always prosecuted under the Japanese law.

On February 12, 2008, the National Police Agency (of Japan) or NPA, released its annual criminal statistics that included activity within the Okinawan prefecture. These findings held American soldiers responsible for 53 crimes per 10,000 U.S. male servicemen, while Okinawan males held a crime rate of 366 crimes per 10,000. The crime rate found a U.S. servicemen in Okinawa to be 86% less likely to commit a crime than that of an Okinawan male.

U.S. Forces Japan designated 22 February as a Day of Reflection for all U.S. military facilities in Japan, and established the Sexual Assault Prevention and Response Task Force in an effort to prevent similar incidents. In November 2009, Staff Sgt. Clyde "Drew" Gunn, a U.S. Army soldier stationed at Torii Station was involved in a hit-and-run accident of a pedestrian in Yomitan Village on Okinawa. Later, in April 2010, the soldier was charged with failing to render aid and vehicular manslaughter. Staff Sgt. Gunn, of Ocean Springs, Mississippi, was eventually sentenced to 2 years and 8 months in jail on October 15, 2010.

Osprey deployment in Okinawa

In October 2012, twelve Bell Boeing V-22 Osprey were transferred to the US Marine Corps Air Station Futenma to replace aging Vietnam-era Boeing Vertol CH-46 Sea Knight helicopters in Okinawa, greatly increasing the safety, capability and range of the Marines who are charged with Japan"s defense as well as regional security. Then in October 2013, an additional 12 Ospreys arrived, again to replace CH-46 Sea Knights, increasing the number of Ospreys to 24. Japanese Defence Minister Satoshi Morimoto explained the Osprey aircraft is safe adding that two recent accidents were "caused by human factors".

Facilities

List of current facilities

The USFJ headquarters is at Yokota Air Base, about 30 km west of central Tokyo.

The U.S. military installations in Japan and their managing branches are as follows:

In Okinawa, U.S. military installations occupy about 10.4 percent of the total land usage. Approximately 74.7 percent of all the U.S. military facilities in Japan are located on the island of Okinawa.

List of former facilities

The United States has returned some facilities to Japanese control. Some are used as military bases of the JSDF; others have become civilian airports or government offices; many are factories, office buildings or residential developments in the private sector. Due to the Special actions committee on Okinawa, more land in Okinawa is in the process of being returned. These areas include—Camp Kuwae , MCAS Futenma, areas within Camp Zukeran , about of the Northern Training Area, Aha Training Area, Gimbaru Training Area (also known as Camp Gonsalves), small portion of the Makiminato Service Area (also known as Camp Kinser), and Naha Port.

Army:

*Army Composite Service Group Area (later, Chinen Service Area), Nanjo, Okinawa